"Comprehensive wiring system engineering acceptance specification" GB 50312 - 2007.
Cable bridges and trunking installation should meet the following requirements:
1, the bridge and trunking installation position should be in line with the requirements of the construction drawings, the left and right deviation should not be more than 50mm.
2, bridges and trunking level deviation per meter should not exceed 2mm. /p>
3, vertical bridges and trunking should be vertical with the ground, vertical deviation should not exceed 3mm.
4, trunking cut-off and two trunking splices should be smooth, no burr.
5, hanger and bracket installation should be kept vertical, neat and firm, no skew phenomenon.
6, metal bridges, trunking and metal pipe sections should be well connected and firmly installed.
7, the use of ceiling support column cable deployment, the support point should avoid the ground trench and wire location, support should be firm.
Expanded
1, in the engineering design, the layout of the bridge should be based on economic rationality, technical feasibility, operational safety and other factors to determine the optimal program, but also to fully meet the construction and installation, maintenance and cable laying requirements.
2, the bridge is laid horizontally from the ground height is generally not less than 2.5m, vertically laid from the ground 1.8m below the part of the metal cover should be added to protect, but laying in the electrical special room, except. Cable tray horizontal laying in the equipment jacket or on the pavement and less than 2.5m, should take protective grounding measures.
3, bridges, trunking and its support hangers used in corrosive environments, corrosion-resistant rigid materials should be used to manufacture. Or take anti-corrosion treatment, anti-corrosion treatment should meet the requirements of the project environment and durability. Requirements for high corrosion resistance or clean places, it is appropriate to use aluminum alloy cable trays.
4, the bridge in the fire requirements of the section, can be added in the cable trapezoid, tray with fire-resistant or flame-retardant properties of the board, nets and other materials constitute a closed or semi-enclosed structure, and to take in the bridge and its support bracket surface brush fireproof coatings and other measures, and its overall fire performance should meet the requirements of the relevant national norms or standards. In the engineering fire requirements of the place, it is not suitable to use aluminum alloy cable tray.
5, the need to shield electromagnetic interference cable lines. Or have to protect the external shadow n to such as outdoor sunshine, oil, corrosive liquids, flammable dust and other environmental requirements. Should be used without holes tray type cable tray.
6, in places where dust is likely to accumulate, the cable tray should be used cover; in the public **** channel or outdoor across the road section. The bottom of the bridge should be padded or use a non-porous tray.
Baidu Encyclopedia - Cable Tray
Baidu Encyclopedia - Acceptance Specification for Comprehensive Wiring Engineering